Question

1. a random sample of students from tarheel academy, a kindergarten through twelfth - grade private school in north carolina, was selected and their height (in centimeters) and age (in years) were recorded. this information is in the table shown.

age (years) 5 6 6 8 9 9 10 12 15 15 16 18
height (cm) 114 120 116 122 130 139 138 145 163 167 179 181
a. identify the explanatory variable and the response variable.
explanatory - age
response - height
c. what scale would be an appropriate for the vertical axis?

1. according to a recent article from a business magazine, “employees who stay in companies longer than 2 years can expect an annual salary increase based on the number of years loyal to that company”. the table shows the number of years of employment and the current annual salary for a random sample of employees in comparable jobs at a large company.

number of years of employment 10 6 9 15 4 10 18 11
current annual salary (in thousands of dollars) 97.3 88.7 94.2 121.8 85.3 100.5 124.7 100.8
a. create a scatterplot for these data.
b. describe the relationship between number of years of employment and current annual salary.

Explanation:

4.

Step1: Identify variables

The explanatory variable is the one thought to influence the other. Age likely influences height, so age is the explanatory variable and height is the response variable.

Step2: Horizontal - axis variable

The explanatory variable goes on the horizontal axis. So age goes on the horizontal axis.

Step3: Determine vertical - axis scale

The heights range from 114 cm to 181 cm. A scale like 10 - unit intervals starting from 110 (e.g., 110, 120, 130, etc.) would be appropriate.

Step1: Create scatter - plot

Plot the number of years of employment on the x - axis and the current annual salary on the y - axis. Each pair of values (number of years, salary) is a point on the scatter - plot.

Step2: Analyze relationship

As the number of years of employment increases, the current annual salary generally seems to increase. There is a positive linear relationship.

Answer:

a. Explanatory variable: Age; Response variable: Height
b. Age
c. A scale with 10 - unit intervals starting from 110 (e.g., 110, 120, 130, 140, 150, 160, 170, 180, 190)

5.